Drill-cutter.



L. A. GODBOLD AND H. W. FLETCHER.

DRILL CUTTER.

APPLICATION FILED JUNE 16. I919.

Pafented Nov. 4, 1919.

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LOUIS A. GODBOLD .AIND HAROLD W. FLETCHER, OF HOUSTON, TEXAS.

DRILL-CUTTER.

Application filed June 16, 1919.

To all whom it may concern:

Be it known that we, LoUIs A. Gomsonn in boring wells or mines'in earth, rock, or

,tate.

other similar formation. The invention is designed as an improvement on the prevlous patent to H. R. Hughes on a roller boring drill, Serial No. 979,496, patented December An object of our invention is to provide a bearing and locking means for the rotatable cutters on a roller boring drill which will be simple in structure and easily detachable.

Another obj ect is to so construct the bushing on a drill cutter that the cutter and bushing may be assembled at the shop and readily attached to the cutter shaft in the field without being taken apart, thereby preserving the bearings clean at all times.

In the drawings forming a part of this specification, and wherein like parts are deslgnated by like numerals, in bot-h the views, Figure 1 is a central. longitudinal section of a cutter, and the bushing used therewith, embodying our invention. 7 Fig. 2 is a bottom plan view, partly diagrannnatic, illustrating the same taken on the line 2-2 of Fig. 1.

Our invention is adapted to be used especially with gutters so formed as to inclose the end of the cutter shaft and the bushing thereon. lVe have illustrated a frusto-conical shaped cutter such as is employed on the so-called Hughes cone-bit wherein the rotating cutters are approximately conical in shape. The cutter is mounted upon a shaft or\ pin, preferably made integral with the lower end of the head 2 of the bit. 7 Said shaft projects inwardly from the flat face 3 of an inclined slot cut in the lower end of the bit. This shaft 1 is threaded for attachment to a tapered bushing 4, upon which the frusto-conical cutter 5 is adapted to ro The cutter 5 has a flattened forward end 6 and is provided with radial teeth 1 extending from the forward end 6 inward toward the head of the bit. The inner face Specification of Letters Patent.

Patented Nov. 4, 1919.

Serial No. 304,508.

of the cutter is also tapered, as shown at S, and provided with slots or grooves 9 which have a slight disintegrating action upon material on the outer surface of the bore hole. Between the rotatable cutter and the flattened face 3 of the bit is provided an antifriction washer 10. This washer is locked against rotation with the cutter by means of a dowel pin 11, said pin being flush with the face of the washer at its outer end. To provide a means for locking the cutter 6 upon the bushing 4 the inner end of the said bushing is reduced in diameter to provide a recess 12 within which an annular locking ring 13 is adapted to seat. This locking ring is threaded on its outer periphery for attachment to the inner face of the cutter 5. It has been previously customary in assembling this device to thread the bushing 1 upon the shaft 1, havingfirst introduced the inner reduced end of the bushing 1 into the locking ring 13. hen the bushing has been threaded securely upon the shaft 1 the locking ring 13 has been held stationary by means of a pin or anchoring device introduced through a. passage in the head of the bit and through the washer 10. The cutter 5 was then threaded upon the locking ring 13 in an obvious manner. This has made it necessary, in putting the cutter upon the bit in the field, to eXposethe bushing 4 to dirt or watercontaining grit and mud while the cutter 5 is threaded over the end of the bushing and onto the locking ring 13.

In our present invention we form cylindrical recesses upon opposite sides of the cutter and through the locking ring and bushing. The said recess is tapered somewhat, being larger in the cutter, as shown at 14, somewhat reduced in diameter and threaded at 15 into the locking ring 13, and

having a still further reduced opening 16 in the bushing, registering with the other openings. In the outer face of the locking ring 13, and at a position at right angles to the recesses 14 and 15, are bored small recesses 17 into which a spanner wrencl. may be inserted in order to tighten the locking ring 13 within its seat in the cutter 5.

In assembling our improved cutter the bushing 4 is inserted within the recess in the cutter, the locking ring is then threaded within its seat so as to hold the cutter rotatable upon the bushing. A small pin or -I wrench may fit within the opening'16 in the bushing. When the wrench is thus 1n- \serted, the cutter, locking ring, and bushing are held rigidly together and may be screwed downward over the pin or shaft 1. When thus secured on said shaft, the wrench 18 is withdrawn and the holes or recesses 14; and 15 are closed by means of a set screw or locking pin 20 inserted through the opening 14a'in the cutter and threaded 20 within the recess 15 in the locking ring, ytl'rus holding the cutter and locking ring "rigidly together. The head of the screw 20 isformed with a polygonal recess into "L -W-hich a reduced end 24 of the wrench 18 25 may"'fit',;to:-operate same. The screw 20 does not enter the recess 16 in the bushing, however, so that the cutter and locking ring will be free to rotate upon the bushing and V will be held against removal therefrom by the fact that the locking ring is seated within the recess 12 in the bushmg.

This means 'of locking the cutter upon the bushing makes it possible to assemble the cutter, the bushin and the lockin ring in the shop so'that t ere will be no anger of water or grit or other slmilar foreign substance obtaining entrance about the bearing surfaces upon which the cutter rotates.

The bearings are lubricated in this-em- 40 bodiment ofour'invention in the same man ner as shown in the Hughes patent previously referred to.

head of the bit conduct lubricant from a containing chamber down through the shaft of the pin 1 so that the same will issue at 22 upon the inner surface of the bushing and will pass through .a smaller duct or channel 23'upon the outer surface of the bushing and thus serve to keep the bear- Passages 21 in the ingsurfaces supplied with lubricant at all times. v

Having thus described our invention, the

further objects and advantages -of which,

will be obvious, what we claim as new arid desire to protect by Letters Patent is:

1. In a device of the character described a rotatable cutter, said cutter being provided with a tapered bearin g recess on its. inner fade, a tapering bushing adapted to fit therein, a locking ring threaded on the inner face of said cutter, and fitted within an annular recess in said bushing, said bushing being provided with a threaded recess for attachment to a cutter shaft and means to temporarily lock said cutter, locking ring and the'bushing non-rotatably to- .gether for the purpose described.

2. In a device of the character described, a bushing, acuttersurrounding-said bush-- ing, a locking ring fitting within a recess in said bushing and secured to said .cutter, said cutter, locking ring, and bushing having opposite openings therein, said openings adapted to be registered to receive a retaining pin and a setfscrew adapted to fit, within the opening in said cutter and to be threaded into said locking ring to close said opening when desired.

3. In a device of the character described,

a cutter shaft, a bushing, threaded thereon,

a cutter inclosin the end of. said bushing and shaft, a lockmg ring to secure said out ter rotatably on. said bushing and means to screw or unscrew said .bushing on to or from said shaft while said cutter is mounted thereon. x

4. In a device of the character described,

- a cutter shaft, a bushing, a cutter fitted over and inclosing one end of said bushing, means to lock said cutter rotatably on said bushing and means to attach or detach said bushing on said shaft while the cutter is locked thereon.

In testimony whereof, we hereunto aflix our signatures this the 6 day of June, 1919.

LOUIS A. GODBOLD. HAROLD W. FLETCHER.

Correction in Letters Patent No. 1,320,384.

It is herebycertified thattin Letters Patent No. 1,320,384, granted November 4,

1919, upon the application of Louis A. Godbold and Harold W; Fletcher, of Houston, Texas, for an iniprovement in DrilLCutters, an error appears in the printed specification requiring correction as follows: Page 2, line 80, claim 3, after the word bushing strike out the comma; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Otfice.

Signedand sealed this 6th day of January, A. D., 1920.

I M. H. COULSTON,

Acting Commissioner of Patents.

[SEAL] 

